Substrate processing apparatus, substrate processing method and non-transitory storage medium

ABSTRACT

There is provided a substrate processing apparatus to perform a predetermined process on a substrate on which a pattern mask is formed, comprising a compartment mechanism configured to switch between a compartmented state and an open state. The compartmented state includes a first section having the evaporation source formation part, and a second section configured to transfer the substrate between an outside of processing vessel and a mounting table. The substrate processing apparatus comprises a substrate transfer hole formed in the processing vessel and configured to open and close with respect to the second section being in the compartmented state; and an exhaust hole formed to connect to the second section and configured to exhaust the second section in the compartment state to remove a solvent atmosphere of the second section.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Japanese Patent Application No.2011-289676, filed on Dec. 28, 2011, in the Japan Patent Office, thedisclosure of which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

The present disclosure relates to a substrate processing apparatus, asubstrate processing method and a non-transitory storage medium, forimproving roughness of a pattern mask.

BACKGROUND

When manufacturing semiconductor devices, LCD (Liquid Crystal Device)substrates or the like, a predetermined pattern mask is formed on asemiconductor wafer (hereinafter, referred to “wafer”) by applying aresist liquid on the surface of the wafer, exposing the wafer anddeveloping the wafer. It has been conventionally known that fineasperities are formed on the surface of a resist pattern after thedevelopment process, which may have an undesirable effect on a patternline width when a subsequent etching process is performed. In order toresolve the above problem, a smoothing process has been proposed toimprove a line edge roughness (LER) or a line width roughness (LWR) ofthe resist pattern.

This smoothing process is performed by forming an atmosphere of asolvent vapor to be used to dissolve the resist in a processing vessel,exposing the resist pattern to the atmosphere, and swelling a surfacelayer portion of the resist pattern. By performing the smoothingprocess, the surface layer portion is dissolved by the solvent and issmoothed. As a result, the surface roughness of the resist pattern isimproved and the shape of the pattern is corrected.

In the above described smoothing process, however, other wafers that arein queue outside the processing vessel may be affected by proximity tothe processing vessel. Thus, there is a need to fully exhaust theinterior of the processing vessel and reduce a concentration of theremaining solvent to a predetermined reference value or less, in orderto contain the effect on the other wafers, before a subsequent wafer tobe processed is carried into the processing vessel after the processingvessel is opened and a processed wafer is carried out. However, such anexhaust process requires a considerable amount of time, which causesdeterioration in throughput. The problem of throughput deteriorationduring the exhaust process has not been resolved in the conventionaltechnique.

SUMMARY

The present disclosure provides a substrate processing apparatus and asubstrate processing method for smoothing a surface of a pattern maskformed on a substrate, which is capable of preventing the leakage of thesolvent from a processing vessel and the deterioration of throughput.

According to one embodiment of the present disclosure, a substrateprocessing apparatus to perform a predetermined process on a substrateon which a pattern mask is formed by exposure and developmenttreatments, comprising: a processing vessel having a process space; amounting table installed in the process space and configured to mountthe substrate thereon; a heating part configured to heat the substratemounted on the mounting table to a temperature higher than a dew-pointtemperature of a solvent; an evaporation source formation part installedin the process space, the evaporation source formation part configuredto supply the solvent to process the substrate in a saturated vaporatmosphere of the solvent within the process space; a compartmentmechanism configured to switch between a compartmented state and an openstate, wherein the compartmented state includes a first section havingthe evaporation source formation part installed in the process space,and a second section configured to transfer the substrate between theoutside of the processing vessel and the mounting table, wherein thecompartmented state represents a state where the first section and thesecond section are partitioned such that atmospheres of the first andsecond sections are blocked from each other, and wherein the open staterepresents a state where the atmospheres of the first and secondsections are opened to each other; a substrate transfer hole formed inthe processing vessel and configured to open and close with respect tothe second section being in the compartmented state; and an exhaust holeformed to connect to the second section and configured to exhaust thesecond section in the compartment state to remove a solvent atmosphereof the second section.

According to another embodiment of the present disclosure, a substrateprocessing method of performing a predetermined process onto asubstrate, on which a pattern mask is formed by exposure and developmenttreatments, comprising: mounting the substrate on a mounting tableinstalled in a process space formed in a processing vessel; heating thesubstrate mounted on the mounting table by a heating part to atemperature higher than a dew-point temperature of a solvent;evaporating the solvent from an evaporation source formation partinstalled in the process space opposite to the entire surface of thesubstrate to form an internal atmosphere of the process space to asaturated vapor atmosphere of the solvent; forming a compartmented stateby a compartment mechanism; the compartmented state representing a statethat a first section, in which the evaporation source formation part isinstalled in the process space, and a second section for transferringthe substrate between the outside of the processing vessel and themounting table, are partitioned such that atmospheres of the first andsecond sections are blocked from each other; forming an open state bycompartment mechanism, the open state representing a state that theatmospheres of the first and second sections are opened to each other;and exhausting the second section when in the compartmented state andremoving a solvent atmosphere of the second section.

According to yet another embodiment of the present disclosure, anon-transitory computer-readable storage medium for use in a substrateprocessing apparatus which performs a predetermined process to asubstrate on which a pattern mask is formed by exposure and developmenttreatments, the storage medium storing a computer program for causing acomputer to execute the substrate processing method.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the presentdisclosure, and together with the general description given above andthe detailed description of the embodiments given below, serve toexplain the principles of the present disclosure.

FIG. 1 shows a longitudinal sectional view of a substrate processingapparatus according to some embodiments.

FIG. 2 is shows a traverse sectional view of the substrate processingapparatus shown in FIG. 1.

FIG. 3 shows a schematic perspective view of a processing vessel, acooling arm and an exhaust arm, which are installed in the substrateprocessing apparatus, according to some embodiments.

FIG. 4 shows a perspective view of each lower side of the cooling armand the exhaust arm, which are installed in the substrate processingapparatus, according to some embodiments.

FIG. 5 shows a front view of the cooling arm and the exhaust arm,according to some embodiments.

FIGS. 6 to 16 are schematic views illustrating operations of respectiveparts of the substrate processing apparatus, according to someembodiments.

FIG. 17 is a timing diagram illustrating the operations of therespective parts of the substrate processing apparatus, according tosome embodiments.

FIG. 18 is a schematic view showing a resist pattern formed on asubstrate, according to some embodiments.

FIG. 19 shows a longitudinal sectional view of another configuration ofa substrate processing apparatus, according to some embodiments.

FIG. 20 shows a longitudinal sectional view of another configuration ofa substrate processing apparatus, according to some other embodiments.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments, examples ofwhich are illustrated in the accompanying drawings. In the followingdetailed description, numerous specific details are set forth in orderto provide a thorough understanding of the present disclosure. However,it will be apparent to one of ordinary skill in the art that the presentdisclosure may be practiced without these specific details. In otherinstances, well-known methods, procedures, systems, and components havenot been described in detail so as not to unnecessarily obscure aspectsof the various embodiments.

Hereafter, a substrate processing apparatus 1 as shown in FIGS. 1 and 2,according to some embodiments, will be described with reference to theaccompanying drawings. The substrate processing apparatus 1 isconfigured to perform a surface treatment to a wafer W (a substrate), onwhich a resist pattern mask is formed by exposure and developmentprocesses, for improving roughness of the pattern mask. FIGS. 1 and 2show longitudinal and traverse sectional views of the substrateprocessing apparatus 1, respectively. The substrate processing apparatus1 comprises a processing vessel 11 configured to form a processatmosphere, a cooling arm 51 and an exhaust arm 61, both of which arecapable of movement for advancing to and retreating from the processingvessel 11, and a housing 71.

As shown in a schematic perspective view in FIG. 3, the processingvessel 11 is formed, for example, into a flat rectangular shape, and theinterior of the processing vessel 11 is formed to have a process space10 for processing the wafer W. The processing vessel 11 is divided intoan upper part and a lower part, where the lower part is a base 12 andthe upper part is a cover 13. In a lateral side of the processing vessel11 facing a wafer transfer path, a gap between the base 12 and the cover13 is a transfer port 14 for transferring the wafer W. A gap between thebase 12 and the cover 13 in a lateral side opposite to the transfer port14 is an advance-retreat port (opening for movement) 15 through whichthe cooling arm 51 and the exhaust arm 61 are advanced to and retreatedfrom the process space 10. For illustrative purpose, the transfer port14 side is referred to as a forward side and the advance-retreat port 15side is referred to as a backward side.

The base 12 comprises sidewalls 16 surrounding side portions of theprocess space 10 and a stage 21 as a bottom portion of the process space10. The stage 21 for use as a process mounting table is surrounded bythe sidewalls 16 and is horizontally formed. The sidewall 16 in theforward side about the stage 21 is formed to be higher than the surfaceof the stage 21 such that the leading end portion (the forward portion)of the cooling arm 51 coming into the processing vessel 11 can bebrought into contact with the sidewall 16 in the forward side.

The stage 21 is includes heaters 22 (heating part) therein configured toheat the wafer W mounted on the stage 21 to a temperature that is higherthan a dew-point temperature of a solvent and lower than a boiling pointof the solvent (which will be described later). Further, the stage 21includes three holes 23 a perforated in a thickness direction of thestage 21 and three elevating pins 23 inserted into and passed throughthe holes 23 a. Leading ends of the elevating pins 23 are moved upwardand downward on the surface of the stage 21 by an elevating mechanism24. The elevating pins 23 and the elevating mechanism 24 constitutes amount and transfer mechanism for the wafer W.

The cover 13 includes a ceiling wall 17 of the processing vessel 11 andsidewalls 18 surrounding side portions of the process space 10. In thesidewalls 18, the sidewall 18 on the forward side is formed to be lowerthan a solvent holding plate 33 (which will be further described later)such that the leading end side of the exhaust arm 61 coming into theprocessing vessel 11 is in contact with the sidewall 18 in the forwardside. The cover 13 is configured to be moved upward and downward by anelevating mechanism 19.

A shutter 36 is installed at the sidewall 18 of the cover 13 in theforward side. The shutter 36 is movable upward and downward with respectto the cover 13 to open and close the transfer port 14. Further, ashutter 37 is installed at the sidewall 18 of the cover 13 in thebackward side. The shutter 37 is movable upward and downward withrespect to the cover 13 to open and close the advance-retreat port 15.Block plates 38 are installed in left and right sides of the cover 13and extend downwardly. The block plates 38 are vertically moved with thecover 13 to block gaps between the cover 13 and the base 12 in the leftand right sides of the processing vessel 11 and to prevent an internalatmosphere of the process space 10 from leaking from the left and rightsides of the processing vessel 11 when the cover 13 is moved upwards anddownwards.

In the ceiling wall 17, a flat circular flow path forming part 31 isformed to be surrounded by the sidewalls 18. A circular recess is formedbelow the flow path forming part 31. The recess constitutes a solventsupply region 32. The solvent holding plate 33, which is an evaporationsource formation member, is configured to cover the bottom of thesolvent supply region 32.

The lower surface of the solvent holding plate 33 constitutes anopposite portion facing the wafer W on the stage 21. In the solventholding plate 33, a plurality of solvent supply holes 34 are formed tobe spaced apart from each other. The solvent supply holes 34 areperforated in a thickness direction of the solvent holding plate 33.Solvent supplied to the solvent supply region 32 is spread to the lowersurface of the solvent holding plate 33 through each solvent supply hole34 by a capillary action. The spread solvent is volatilized andevaporated in a region opposed to the entire surface of the wafer W asseen from the wafer W on the stage 21 so that the wafer W is entirelyexposed to the vapor of the solvent. In order to supply the solventvapor to the entire surface of the wafer W as described above, thesolvent holding plate 33 is formed to have a planar shape larger thanthat of the wafer W. The diameter of each solvent supply hole 34 is, forexample, about 0.3 mm to 1 mm. In the flow path forming part 31, heaters35 are provided as a heating part. The temperature of the solventholding plate 33 is controlled by the heaters 35 at a high uniformitythrough the solvent supply region 32. As a result, the solvent spreadingdownwardly through the solvent supply holes 34 is volatilized at a highuniformity in the surface of the solvent holding plate 33 and thesolvent vapor is supplied to the wafer W at a high uniformity, asexplained above.

Also shown in FIG. 1 is a solvent supply source 41 in which the solventis stored. The solvent supply source 41 supplies the solvent to thesolvent supply region 32 through a solvent supply pipe 42. In FIG. 1, V1represents a valve disposed in the solvent supply pipe 42. Anopening/closing of the valve V1 is controlled by a control unit 80(which will be further described later) such that supplying and blockingoperations of the solvent to the solvent supply region 32 arecontrolled. Examples of the solvent may include, but is not limited to,an acetone, propylene glycol methyl ether acetate (PGMEA),cyclohexanone, Propylene glycol monomethyl ether (PGME),Gamma-Butyrolactone (GBL), pyridine, xylene, N-methyl-2-pyrrolidone(NMP), Ethyl lactate, 2-Heptanone, butyl acetate, methyl isobutyl ketone(MIBK), diethyl ether, anisole, Dimethyl sulfoxide (DMSO), m-Cresol, orthe like, which has a function of dissolving a resist film.

A liquid level detection pipe 43 is vertically connected to the solventsupply region 32. In the liquid level detection pipe 43, a lower liquidlevel detecting sensor 44, a tank 45, and an upper liquid leveldetecting sensor 46 are subsequently disposed from the bottom to thetop. The upper end of the liquid level detection pipe 43 is branchedinto a liquid drain pipe 47 connected to a liquid drain path, and a gassupply pipe 49 connected to an N2 gas supply source 48. In FIG. 1, V2and V3 represent a valve disposed in the liquid drain pipe 47 and avalve disposed in the gas supply pipe 49, respectively. As will bedescribed later, when discarding the solvent, the valve V2 is closed topressurize the liquid level detection pipe 43. However, the valve V2 isopened to supply the solvent from the solvent supply source 41 to theliquid level detection pipe 43 except for the discarding operationabove. When discarding the solvent, the valve V3 is opened to supply theN2 gas from the N2 gas supply source 48 to the liquid level detectionpipe 43. However, the Valve V3 is closed except for the discardingoperation above. The valve V3, the gas supply pipe 49 and the N2 gassupply source 48 constitute a solvent exhaust mechanism.

Next, the cooling arm 51 and the exhaust arm 61 will be described withreference to FIGS. 4 and 5, showing a lower perspective view and a frontview of the cooling arm 51 and the exhaust arm 61. The cooling arm 51has a cooling plate 52 constituting a mounting portion for cooling. Thecooling plate 52 is formed into a horizontal and rectangular shape. Forexample, a cooling water path (not shown) is formed inside the coolingplate 52, and the wafer W mounted on the surface of the cooling plate 52is cooled by heat exchange with the cooling water. As shown in FIG. 5,when seen from a front-back direction, the left and right sides of thecooling plate 52 are bent upward to form upward-extended plates 53.Further, the left and right sides of the backward portion of the coolingplate 52 are extended downward to form support parts 54. The supportparts 54 are connected to a drive mechanism (not shown). By the drivemechanism, the cooling arm 51 is movable in the frontward and backwarddirections between a standby section 70 in the rear side of theprocessing vessel 11 and the process space 10 of the processing vessel11 (FIGS. 1 and 2). Two slits 55 are formed in parallel to extend fromthe front side to the back side of the cooling plate 52. When thecooling arm 51 advances into the process space 10, the elevating pins 23may pass through the slits 55.

Next, the exhaust arm 61 constituting a compartment mechanism will bedescribed. As shown in FIG. 3, the exhaust arm 61 is formed to cover thecooling arm 51 and includes a compartment plate 62 positioned above thecooling plate 52. The compartment plate 62 is configured to be ahorizontal and rectangular shape. As shown in FIG. 5, when seen from thefront-back direction, the left and right sides of the compartment plate62 are bent vertically downward to form downward-extended plates 63. Thedownward-extended plates 63 are formed to insert the cooling arm 51between the left and right sides thereof. The downward-extended plates63 and the upward-extended plates 53 of the cooling arm 51 are combinedto form a flow path toward an exhaust section 50 as a curved structure,as seen from a solvent vapor of an adjacent section 60 (which will befurther described later). This prevents the solvent vapor from cominginto the exhaust section 50.

In the backward side of the compartment plate 62, an exhaust part 64 isdisposed between the downward-extended plates 63. The exhaust part 64 isconfigured to block the backward side of the exhaust section 50 (wherethe exhaust section 50 is configured to be surrounded by the coolingplate 52 and the upward-extended plates 53 of the cooling arm 51 and thecompartment plate 62) such that a position of the front end of theexhaust arm 61 and a position of the front end of the cooling arm 51 arealigned with each other. A slit-like exhaust hole 65 extending in aleft-right direction is formed in the exhaust part 64, which makes itpossible to exhaust and remove an internal atmosphere of the exhaustsection 50. The exhaust hole 65 is connected to a tank 81 (which will befurther described later) through a valve V4. As shown in FIGS. 4 and 5,gaps 66 are formed between the exhaust part 64 and the downward-extendedplates 63 such that the upward-extended plates 53 of the cooling arm 51can be passed through the gaps.

The back ends of the downward-extended plates 63 extend downward to formsupport parts 67. The support parts 67 are connected to a drivemechanism (not shown). By the drive mechanism, the exhaust arm 61 ismovable in the forward and backward directions between the standbysection 70 defined at the rear side of the processing vessel 11 and theprocess space 10 of the processing vessel 11 (FIG. 1). A slit-like purgegas discharging hole 68 extending in a left-right direction is formed ata front end portion of the lower surface of the compartment plate 62.The purge gas discharging hole 68 is formed to discharge the N2 purgegas to the inclined backward side of the exhaust section 50 forpreventing a solvent atmosphere of the exhaust section 50 from flowingoutside the processing vessel 11. The purge gas discharging hole 68 isconnected to the N2 gas supply source 48 through valve V5.

A liquid-receiving portion 69 of a circular recess shape is formed atthe upper surface of the compartment plate 62. When the exhaust arm 61enters into the processing vessel 11, the liquid-receiving portion 69 isplaced opposite to the lower side of the solvent holding plate 33, andserves to receive and remove unnecessary solvent discharged from thesolvent holding plate 33 and serves to remove an atmosphere of the upperside of the compartment plate 62. For this reason, the liquid-receivingportion 69 is formed to be larger than the solvent holding plate 33. Awaste channel 69 a is connected to the liquid-receiving portion 69.Further, the waste channel 69 a is connected to the tank 81 through avalve V6.

Referring back to FIGS. 1 and 2, the housing 71 is formed to surroundthe processing vessel 11 and the standby section 70 outside theprocessing vessel 11, where the cooling arm 51 and the exhaust arm 61may be on stand by. An exhaust hole (or outer exhaust hole) 72 is formedat the rear side of the housing 71. When the shutter 37 is opened toprovide an opening for the advance-retreat port 15, the exhaust hole 72removes the solvent atmosphere discharged from the process space 10 andprevents the leakage of the solvent atmosphere to the outside of thehousing 71. The exhaust hole 72 is connected to the tank 81 through avalve V7. In the front side of the housing, a transfer port 73 fortransferring the wafer W to the process space 10 is formed.

The tank 81 is installed in a clean room and includes a front chamber82, a back chamber 83, and a partition wall 84 for partitioning thefront chamber 82 and the back chamber 83. A hole 85 for circulating airfrom the front chamber 82 to the back chamber 83 is formed above thepartition wall 84. A liquid drain channel 82 a is connected to the frontchamber 82, and an exhaust mechanism 86 such as a vacuum pump isconnected to the back chamber 83. The exhaust mechanism 86 is capable ofperforming the exhaust operation for respective parts of the substrateprocessing apparatus 1 through the tank 81 as described above. Coolingwater paths 87 are formed at walls of the front chamber 82 and thepartition wall 84 in the tank 81. Cooling water whose temperature iscontrolled by a temperature control unit (not shown) installed outsidethe tank 81 is fed to the cooling water paths 87, and then controlled bythe temperature control unit and fed back to the cooling water paths 87.

The solvent, the dissolved resist material and the like, which wereexhausted from the processing vessel 11 and the housing 71 and directedto flow into the front chamber 82, are cooled and liquefied in the frontchamber 82, and then discharged through the liquid drain channel. Then,an atmosphere where the solvent and the dissolved resist material areremoved is flown into the back chamber 83 and is exhausted. That is, thetank 81 serves to separate air and liquid and remove them. Further,since the solvent gas exhausted from the processing vessel 11 and thehousing 71 is a gas of high temperature and high humidity, and isliquefied at a temperature of the clean room, e.g., about 23 degrees C.,the solvent gas may be naturally cooled without forming cooling waterpaths 87. However, if cooling water paths 87 are formed, the separationof the gas and the liquid can be further improved. Instead of thecooling water, a temperature-controlled gas may be fed to the coolingwater paths 87.

The substrate processing apparatus 1 may be controlled by the controlunit 80. The control unit 80, for example, may be configured with acomputer, and includes a program, a memory, and a Central ProcessingUnit (CPU). A command (each step), which allows the control unit 80 toprovide a control signal to respective parts of the substrate processingapparatus 1 and allows predetermined surface treatment to be performed,may be stored in the program. The program is stored in acomputer-readable storage medium, for example, a storage part such as aflexible disk, a compact disk, a hard disk, Magneto Optical (MO) disk, amemory card or the like, and installed in the control unit 80. Herein,the program may include a program for controlling the operations ofopening/closing of each of the valves, increasing the temperature withthe heaters 22 and 35, moving the cooling arm 51 and the exhaust arm 61,and elevating the elevating pins 23. The respective parts are controlledaccording to a predetermined process recipe stored in the memory of thecontrol unit 80.

Hereinafter, a wafer process operation performed by the substrateprocessing apparatus 1, according to some embodiments, will be describedwith reference to FIGS. 6 to 16, which illustrate operations ofrespective parts of the substrate processing apparatus 1, and FIG. 17,which show a timing diagram for illustrating the operations of therespective parts of the substrate processing apparatus 1. The timingdiagram represents the opening/closing operations of the transfer port14 and the advance-retreat port 15 by the shutters 36 and 37, theadvance/retreat operations of the cooling arm 51 and the exhaust arm 61into/from the process space 10, ON/OFF operations of the supply andexhaust of gas for the respective parts, an elevation operation of thecover 13 and an elevation operation of the elevating pins 23.

Initially, the substrate processing apparatus 1 is in a state where: 1)the transfer port 14 is closed; 2) the cover 13 is positioned at anelevated position; 3) the advance-retreat port 15 is opened and thecooling arm 51 and the exhaust arm 61 are advanced into the processspace 10; 4) the leading ends of the cooling arm 51 and the exhaust arm61 are brought into contact with an internal wall of the processingvessel 11 to partition the exhaust section 50 surrounded by the exhaustarm 61 and the cooling arm 51 from the surrounding area. For the sake ofsimplicity, in the process space 10, the surrounding area of the exhaustsection 50 defined as above may be referred as an adjacent section 60.After the exhaust section 50 is partitioned as above, exhausting thehousing 71 through the exhaust hole 72 of the housing 71 and exhaustingthrough the liquid-receiving portion 69 are performed.

Thereafter, the solvent is supplied from the solvent supply source 41 tothe solvent supply region 32 and directed to flow into the liquid leveldetection pipe 43. Then, a liquid level of the solvent in the liquidlevel detection pipe 43 is gradually elevated as shown in FIG. 6. Atthis time, the solvent dropped through the solvent supply holes 34 isreceived in the liquid-receiving portion 69 and discharged therefrom. Ifthe tank 45 is filled with the solvent and the upper liquid leveldetecting sensor 46 detects the liquid level of the solvent, the supplyof the solvent to the solvent supply region 32 is stopped. Thetemperature of the stage 21 is increased by the heaters 22 and the lowersurface of the solvent holding plate 33 is heated by the heaters 35 to atemperature lower than that of the stage 21, e.g., 40 degrees C. Then,the solvent is evaporated from the solvent supply holes 34 of thesolvent holding plate 33 to form a solvent vapor, and the solventevaporated from the solvent supply holes 34 is automatically suppliedfrom the solvent supply region 32 to the solvent supply holes 34 by acapillary action.

After the solvent is supplied into the solvent supply region 32 and theliquid level detection pipe 43 as described above, the processing of thewafer W begins. As schematically illustrated in FIG. 17, the wafer W issubjected to a series of processes including: 1) transporting the waferW into the process space 10; 2) controlling a temperature; 3) smoothinga resist mask with the solvent vapor; 4) cooling a processed wafer W;and 5) transporting the processed wafer W out of the process space 10.

The N2 gas is discharged through the purge gas discharging hole 68 ofthe exhaust arm 61. At this time, the exhaust operation through theexhaust hole 65 is performed and a concentration of the solvent in theexhaust section 50, which is partitioned from the adjacent section 60,is decreased. Then, the transfer port 14 is opened and the exhaustsection 50 is exposed to the outside of the processing vessel 11 (attime t1 in FIG. 17). Then, a transfer mechanism 20 advances into theexhaust section 50 while supporting a peripheral portion of the rearsurface of the wafer W as shown in FIG. 7. The elevating pins 23 moveupward to support the rear surface of the wafer W, and the transfermechanism 20 is retreated from the processing vessel 11.

As shown in FIG. 8, the transfer port 14 is closed (at time t2 shown inFIG. 17). When the discharge of the N2 gas from the purge gasdischarging hole 68 is stopped and the exhaust through the exhaust hole65 is stopped, the cooling arm 51 is retreated to the standby section 70(at time t3 shown in FIG. 17). Then, the elevating pins 23 movedownward, and the wafer W is mounted on the stage 21 as shown in FIG. 9(at time t4 shown in FIG. 17). At this time, the temperature of thewafer W is set equal to that of the clean room, e.g., 23 degrees C. Thewafer W is heated by the heaters 22 of the stage 21 to a targettemperature higher than a dew-point temperature of the solvent and lowerthan a boiling point of the solvent, e.g., 50 degrees C. The solventholding plate 33 and the wafer W are partitioned by the exhaust arm 61while the temperature of the wafer W rises, which prevents the solventvolatilized from the solvent holding plate 33 from being condensed andadhered to the wafer W before the volatilized solvent reaches to thetarget temperature. Accordingly, the wafer W can reach the targettemperature while preventing excessive swelling.

When the wafer W reaches the target temperature, the exhaust arm 61 isretreated to the standby section 70, and the advance-retreat port 15 isclosed by the shutter 37. Then, the process space 10 is partitioned andclosed from the standby section 70 as shown in FIG. 10, and the exhaustof the housing 71 through the exhaust hole 72 is stopped. Thereafter,the cover 13 of the processing vessel 11 descends to a process positionas shown in FIG. 11 (at time t5 shown in FIG. 17). The solvent isvolatilized from the solvent holding plate 33 into the process space 10,and the solvent becomes in equilibrium between the process space 10 andthe surface of the solvent holding plate 33 and a saturated vaporatmosphere of the solvent is formed in the process space 10.

At this time, the wafer W is at a temperature adjusted to be higher thanthe dew-point temperature of the solvent and lower than the boilingpoint of the solvent. Accordingly, a phenomenon occurs in whichmolecules of the solvent crash against a resist pattern in the patternmask 9 of the resist to thereby allow the surface of the pattern to beswollen by the solvent, but the solvent is again volatilized by heat ofthe wafer W repeatedly. As a result, as shown in upper and middle stagesof FIG. 18, only a surface layer portion 91 of the pattern mask 9absorbs the solvent to be swollen. Due to the solvent, moleculesconstituting the resist film are soften, dissolved and moved, butinfiltration of the molecules into the pattern mask 9 is prevented. Thisprevents a shape of the pattern from being dissolved or deformed.

As shown in FIG. 12, the cover 13 begins to move upward (at time t6shown in FIG. 17) and gradually returns to the elevated position beforethe cover 13 descends. As a result, a radiant heat to be received by thesolvent holding plate 33 from the stage 21 and the wafer W is graduallyreduced, a temperature of the solvent holding plate 33 is decreased, andan amount of the solvent vapor to be volatilized toward the processspace 10 is also decreased. This suppresses an amount of the solventvapor to be supplied to the wafer W and suppresses and prevents anexcessive solvent from being supplied to the swollen surface layerportion 91. Therefore, the infiltration of the solvent to the inside ofthe pattern mask 9 is can be suppressed. By performing theaforementioned process, rough portions on the surface of the patternmask 9 are smoothed and a variation of the line width of the pattern inthe surface of the wafer W is decreased.

As shown in a lower stage of FIG. 18, the surface layer portion 91 ofthe pattern mask 9 begins to be dried, the cover 13 returns to theelevated position, the wafer W is raised from the stage 21 by theelevating pins 23 (at time t7 shown in FIG. 17), and the exhaust of thehousing 71 through the exhaust hole 72 is resumed. Subsequently, theadvance-retreat port 15 is opened, the cooling arm 51 and the exhaustarm 61 move into the process space 10 through the advance-retreat port15 (at time t8 shown in FIG. 17), and the wafer W is enclosed in theexhaust section 50. The leading ends of the cooling arm 51 and theexhaust arm 61 are brought into contact with the internal wall of theprocessing vessel 11, and the exhaust section 50 is partitioned from theadjacent section 60 outside thereof.

Thereafter, the elevating pins 23 descend, and the wafer W istransferred to the cooling arm 51 and is cooled. While the elevatingpins 23 descend as described above, as shown in FIG. 14, an exhaustoperation is performed through the exhaust hole 65 of the exhaust arm61. Additionally, a discharge of the N2 gas through the purge gasdischarging hole 68 and an exhaust through the exhaust hole 65 areperformed, and a gas stream from the forward side toward the backwardside is formed in the exhaust section 50 (at time t9 shown in FIG. 17).As such, the exhaust operation and the purge gas supply operation areperformed in the exhaust section 50 at a state when the exhaust section50 is partitioned from the adjacent section 60 and where the solventholding plate 33 used as a solvent supply source is installed such thatthe solvent is not introduced into the exhaust section 50, and theconcentration of the solvent is quickly decreased.

Thereafter, as shown in FIG. 15, the transfer port 14 is opened, theexhaust section 50 is exposed to the outside of the processing vessel11, the elevating pins 23 is elevated to separate the wafer W from thecooling arm 51 (at time t10 shown in FIG. 17), the transfer mechanism 20moves into the exhaust section 50, and the elevating pins 23 descend totransfer the wafer W on the transfer mechanism. The transfer mechanism20 is retreated to carry out the wafer W. Even when the wafer W iscarried out, the gas stream is continuously formed in the exhaustsection 50, and thus the leakage of the solvent atmosphere from theexhaust section 50 to the outside of the processing vessel 11 isprevented or further reduced.

The transfer port 14 is closed, and the discharge of the N2 gas throughthe purge gas discharging hole 68 and the exhaust through the exhausthole 65 are stopped. By the exhaust through the liquid-receiving portion69 and the exhaust hole 72, the solvent vapor created from the solventholding plate 33 is removed. Accordingly, the introduction of thesolvent vapor into the exhaust section 50 is prevented. After the gasstream is formed in the exhaust section 50 and the solvent concentrationof the exhaust section 50 is decreased, the transfer port 14 is openedand a subsequent wafer W is carried in the processing vessel 11. Thenext wafer W is processed in a similar manner as described for theprevious wafer W and is carried out the processing vessel 11.

If the loading of the wafer W in the substrate processing apparatus 1and the treatment process are continuously performed as described above,the tank 45 storing the solvent therein becomes empty and the liquidlevel of the solvent in the tank 45 is detected by the lower liquidlevel detecting sensor 44, the substrate processing apparatus 1 stopsthe treatment process for the wafer which is processed when the liquidlevel is detected and a solvent supplement operation is performed beforetransferring a next wafer W into the processing vessel 11. As shown inFIG. 6, such supplemental operation is performed similarly in the casewhere the solvent is supplied to the solvent supply region 32 at thestart of the operation of the substrate processing apparatus 1. And, thesolvent is supplied to the liquid level detection pipe 43 through thesolvent supply region 32 until the upper liquid level detecting sensor46 detects the liquid level of the solvent.

For example, when the operation of the substrate processing apparatus 1is stopped after a predetermined number of wafers W are processed, thevalve V3 is opened and the N2 gas is supplied to the liquid leveldetection pipe 43 as shown in FIG. 16. The solvent stored in the liquidlevel detection pipe 43, the tank 45 and the solvent supply region 32 ispressurized, and the solvent is forced from the solvent supply holes 34of the solvent holding plate 33 into the liquid-receiving portion 69 ofthe exhaust arm 61 and then it is removed from the liquid-receivingportion 69. Thereafter, exhaust from the housing 71 through the exhausthole 72, and exhaust/drain from the liquid-receiving portion 69 of theexhaust arm 61 are stopped.

In the substrate processing apparatus 1, in some embodiments, theexhaust arm 61 and the cooling arm 51 may be advanced to have theexhaust section 50 isolated from the surrounding area in the processingvessel 11 where a saturated vapor atmosphere of the solvent vapor isformed, and the exhaust section 50 is locally exhausted by the exhausthole 65 of the exhaust arm 61. Thus, the solvent concentration of theexhaust section 50 can be quickly decreased. As a result, leakage of thesolvent vapor from the transfer port 14, which is opened/closed withrespect to the exhaust section 50, to the outside of the processingvessel 11 can be restrained. Further, since a volume of the exhaustsection 50 relative to the process space 10 could be restrained, thesolvent concentration of the exhaust section 50 can be quickly decreasedand the processed wafer W can be quickly carried out and the subsequentwafer W can be quickly carried in with minimized effects due to theprocessing of the previous wafer W. As a result, the throughput isimproved.

Further, since the substrate processing apparatus 1 is configured suchthat the heated wafer W is cooled by the cooling arm 51 during removingthe solvent atmosphere of the exhaust section 50, it is not necessary tocool the wafer W after the wafer W is carried out from the substrateprocessing apparatus 1. Therefore, the throughput can be improved. Inaddition, the substrate processing apparatus 1 is advantageous in thatthe cooling arm 51 is provided to form the exhaust section 50 asdescribed above. By this configuration, the exhaust section 50 isseparated from a region of the lower side of the process space 10 andthe volume of the exhaust section 50 can be reduced. However, theexhaust arm 61 is also provided to separate the process space 10 intoupper and lower portions instead of the cooling arm 51, such that asection including the stage 21 in the lower side of the exhaust arm 61may be defined as an exhaust section. In this case, it is preferable torestrain the volume of the exhaust section by controlling a gap betweenthe exhaust arm 61 and the stage 21 and restraining the height of theexhaust section.

Further, the substrate processing apparatus 1 is configured such thatthe solvent is supplied to the lower surface of the solvent holdingplate 33 in the processing vessel 11, and if the solvent isinsufficient, the solvent is automatically supplied. Thus, it is notnecessary to transfer the solvent holding plate 33 to the outside of theprocessing vessel 11 for supplying the solvent to the solvent holdingplate 33. As a result, it is possible to prevent the solvent atmospherefrom being drained to the outside of the substrate processing apparatus1. Further, since there is no need to provide the transfer mechanism fortransferring the solvent holding plate 33 to the outside of theprocessing vessel 11, it is possible to simplify the structure of thesubstrate processing apparatus 1 and to reduce manufacturing cost. Thesolvent holding plate 33 may be formed of a porous body.

In the above embodiments, the wafer W is carried in the process space 10at a state where the temperature of the wafer W is at a temperature ofthe clean room, i.e., the temperature of the wafer W is lower than atemperature of the dew-point temperature of the solvent. However, thewafer W may be transferred to the process space 10 at a state when it isheated to a temperature that is higher than the dew-point temperature ofthe solvent. In this case, the temperature of the wafer W transferred tothe stage 21 is decreased from the temperature when the wafer W iscarried into the process space 10 to a temperature of the stage 21,i.e., to a target temperature, such that the pattern mask 9 is swollenin the saturated vapor atmosphere. That is, until the temperature of thewafer W is decreased from the temperature when the wafer W is carriedinto the process space 10 to the target temperature, no solventmolecules is adhered onto the wafer W and an excessive swelling of thepattern mask 9 can be further prevented.

The embodiment above is configured such that the interior of the housing71 surrounding the processing vessel 11 is exhausted. Alternatively, asupply hole 101 and an exhaust hole 102 through which the N2 gas passesmay be formed in the advance-retreat port 15 as shown in FIG. 19. Whenthe shutter 37 is opened, the N2 gas is supplied through the supply hole101, the exhaust operation is performed through the exhaust hole 102,and a gas stream is formed in the advance-retreat port 15 as indicatedby an arrow in FIG. 19. With this configuration, the atmosphere of theprocess space 10 is obstructed by a gas stream, and leakage of theatmosphere of the process space 10 to the outside can be prevented.

The embodiment above is configured such that the exhaust arm 61 used asa partition member is advanced into the process space 10 to define theprocess space 10, however the present disclosure is not limited thereto.For example, as shown in FIG. 20, openable/closable shutters 103 may beinstalled within the process space 10 to form the process space 10. InFIG. 20, a numerical number 104 represents an exhaust hole formed in thebottom portion of the processing vessel 11. After processing the waferW, the shutter 103 is closed and the solvent holding plate 33 and thestage 21 on which the wafer W is mounted are partitioned. Then, thecircumstance of the stage 21 is exhausted through the exhaust hole andthe N2 gas is supplied through a gas supply hole 105, and thus anatmosphere of a lower side defined by being partitioning by the shutter103 is displaced. Thereafter, the wafer W is carried out through thetransfer port 14 and, and for example, it is transferred to a coolingdevice installed outside the processing vessel 11 and is cooled.

The embodiment above is configured such that the heaters 22 are built inthe stage 21. However, any configuration may be used so long as thewafer W mounted on the stage 21 is heated. For example, a light emittingdiode (LED) may be installed in the processing vessel 11 such that theLED radiates an optical energy to the wafer W for heating. Further, theabove embodiment above is described that the N2 gas is supplied torespective parts of the substrate processing apparatus 1. However, thepresent disclosure is not limited thereto. For example, another gas suchas air may be supplied to the respective parts. According to theembodiment of the present disclosure, a compartment mechanism forpartitioning the process space from the solvent evaporation sourceformation part, and an exhaust hole for exhausting the interior of thecompartmented section and a transfer hole for opening and closing thecompartmented section are configured. Thus, when a substrate used as thewafer W is carried into and out the process space, it is possible toprevent the solvent generated from the solvent evaporation sourceformation part from being leaked outside the processing vessel. Further,since the volume of the partitioned section as an exhaust section insidethe processing vessel is restrained, the exhaust section can be quicklyexhausted, which makes it possible to carry a processed substrate outthe processing vessel and to carry a subsequent substrate into theprocessing vessel. Therefore, it is possible to improve a throughput.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosures. Indeed, the novel methods and apparatusesdescribed herein may be embodied in a variety of other forms;furthermore, various omissions, substitutions and changes in the form ofthe embodiments described herein may be made without departing from thespirit of the disclosures. The accompanying claims and their equivalentsare intended to cover such forms or modifications as would fall withinthe scope and spirit of the disclosures.

What is claimed is:
 1. A substrate processing method of performing apredetermined process onto a substrate, on which a pattern mask isformed by exposure and development treatments, comprising: mounting thesubstrate on a mounting table installed in a process space formed in aprocessing vessel; heating the substrate mounted on the mounting tableby a heating part to a temperature higher than a dew-point temperatureof a solvent; evaporating the solvent from an evaporation sourceformation part installed in the process space opposite to the entiresurface of the substrate to form an internal atmosphere of the processspace to a saturated vapor atmosphere of the solvent; forming acompartmented state by a compartment mechanism; the compartmented staterepresenting a state that a first section, in which the evaporationsource formation part is installed in the process space, and a secondsection for transferring the substrate between the outside of theprocessing vessel and the mounting table, are partitioned such thatatmospheres of the first and second sections are blocked from eachother; forming an open state by compartment mechanism, the open staterepresenting a state that the atmospheres of the first and secondsections are opened to each other; opening and closing a substratetransfer hole formed in the processing vessel with respect to the secondsection being in the partition state; and exhausting the second sectionwhen in the compartmented state and removing a solvent atmosphere of thesecond section.
 2. The method of claim 1, further comprising: moving thecompartment mechanism between a standby section outside the processingvessel and the process space; and opening and closing an opening formoving the partition mechanism in the processing vessel.
 3. The methodof claim 2, further comprising: exhausting a housing which surrounds thestandby section.
 4. The method of claim 2, further comprising: moving amounting part for cooling, wherein the mounting part for cooling isconfigured to be covered by the compartment mechanism and configured tomount and cool the substrate heated by the heating part; andtransferring the substrate from the mounting table to the mounting partfor cooling by a transfer mechanism, wherein the second section isformed between the mounting part for cooling and the partitionmechanism.
 5. The method of claim 2, further comprising: discharging anunnecessary solvent from the evaporation source formation part by anexhaust mechanism to the compartment mechanism; receiving theunnecessary solvent from a liquid-receiving portion formed in thepartition mechanism; and discharging and removing the received solvent.6. The method of claim 2, further comprising: supplying a purge gas tothe second section; purging a solvent atmosphere to an exhaust hole; andremoving the solvent atmosphere of the second section.
 7. The method ofclaim 2, further comprising: supplying the solvent from the solventstoring part storing the solvent therein to solvent supply holes by acapillary action, wherein the solvent supply holes constitute theevaporation source formation part and are formed to be opened toward thesubstrate at an opposite portion formed to face the substrate in theevaporation source formation part.
 8. A non-transitory computer-readablestorage medium for use in a substrate processing apparatus whichperforms a predetermined process to a substrate on which a pattern maskis formed by exposure and development treatments, the storage mediumstoring a computer program for causing a computer to execute thesubstrate processing claim 1.